EEG alterations during treatment with olanzapine

A Case of Complex Partial Seizures Presenting as Acute and Transient Psychotic Disorder

Introduction

Complex partial seizures are focal (CPS) (i.e., start in one area of the brain) and associated with impairment in consciousness. Most of them arise in the temporal region and are characterized by aura, impaired consciousness, and automatisms. CPS that arise in temporal region are most often misdiagnosed as primary psychiatric illness.

Case Report

A 25-year-old male presented with fluctuations in consciousness, aggressive behaviour, hallucination, and delusions of grandeur lasting a few hours. He was diagnosed with acute and transient psychotic disorder according to ICD10 criteria and was treated with intramuscular haloperidol 10mg BID followed by oral olanzapine 10mg. Computed tomography of brain and electroencephalogram were normal. After 15 days he presented again to the outpatient department with complaints of aggressive behaviour and sensory misinterpretations. Video electroencephalogram was recommended, which was not done due to financial constraints. The diagnosis was reconsidered and he was started on oral carbamazepine due to high clinical suspicion, of complex partial seizures, in spite of lack of EEG evidence. He responded well to antiepileptic and symptom remission has maintained well.

Conclusion

Patients presenting with psychosis need careful diagnostic evaluation for other possibilities.

EEG changes in patients on antipsychotic therapy: A systematic review

OBJECTIVES

The objective of the study was to characterize the electroencephalogram (EEG) changes associated with different antipsychotic medications based on the evidence from the literature.

METHODS

A systematic search of the databases Medline, PsycINFO, and PubMed was conducted. The Preferred Items Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in the construction of this systematic review. Primary research articles that reported descriptive EEG results, included comparisons of subjects with and without antipsychotic therapy, and excluded patients with epilepsy were included in the analysis. The outcome was the presence of epileptiform discharges or slowing on EEG. We analyzed pooled data, where possible, from studies with a similar intervention and methodology.

RESULTS

Fourteen articles reporting on a total of 665 patients were reviewed. Among the publications, clozapine was the drug most consistently accompanied by EEG slowing and epileptiform discharges, with an odds ratio of 16.9 (95% confidence intervals (CI): 5.4 to 53.2) and 6.2 (95% CI: 3.4 to 11.3), respectively in the analysis of pooled data. Only one study reported a significant increase in epileptiform discharges with phenothiazine antipsychotic therapy as a group, but the impact of individual drugs was not analyzed separately.

CONCLUSIONS

This systematic review suggests that, among antipsychotics, clozapine most frequently induces EEG slowing and epileptiform discharges. There remains limited data with respect to other individual antipsychotic agents and covariates including drug dose, plasma levels, dose adjustments, and treatment duration that influence EEG changes.

Unsuccessful reduction of high-frequency alpha activity during cognitive activation in schizophrenia

AIMS

Electroencephalogram (EEG) alpha activity during resting state reflects the 'readiness' of an individual to respond to the environment; this includes the performance of cognitive processes. Alpha activity is reported to be attenuated in schizophrenia (SCZ). Understanding the interaction between alpha activity during rest and when cognitively engaged may provide insights into the neural circuitry, which is dysfunctional in SCZ. This study investigated the changes of alpha activity between resting state and cognitive engagement in SCZ patients.

METHODS

Thirty-four SCZ patients and 29 healthy controls (HC) were recruited. EEG was performed in the resting state and during an auditory P300 task. All experimental procedures followed the relevant institutional guidelines and regulations.

RESULTS

In SCZ, high-frequency alpha activity was reduced in the resting state. High-frequency alpha source density was decreased in both the resting-state and a P300 task condition in patients, compared to HC. HC, but not SCZ patients, showed a reduction in high-frequency alpha source density during the P300 task compared to the resting state. The negative correlation between high-frequency alpha source density in the resting state and positive symptoms was significant.

CONCLUSIONS

High-frequency alpha activity in SCZ patients and its unsuccessful reduction during cognitive processing may be biological markers of SCZ.

Electroencephalogram Modifications Associated With Atypical Strict Antipsychotic Monotherapies

BACKGROUND

Antipsychotics produce electroencephalogram (EEG) modifications and increase the risk of epileptic seizure. These modifications remain sparsely studied specifically for atypical antipsychotics. In this context, our study focuses on EEG modifications associated with atypical strict antipsychotic monotherapies.

METHODS

Electroencephalogram recordings of 84 psychiatric patients treated with atypical antipsychotics in strict monotherapy (clozapine, n = 22; aripiprazole, n = 22; olanzapine, n = 17; risperidone, n = 9; quetiapine, n = 8; risperidone long-acting injection, n = 4; and paliperidone long-acting injection, n = 2) were analyzed. The modifications were ranked according to both slowing and excitability scores.

RESULTS

Electroencephalogram modifications (in 51 subjects, 60.71%) were graded according to 4 stages combining general slowing and sharp slow waves and/or epileptiform activities. The presence of sharp or epileptiform activities was significantly greater for clozapine (90.9%) compared with other second-generation antipsychotics (aripiprazole, 50%; olanzapine, 58.8%; quetiapine, 37.5%; risperidone, 44.4%). Age, duration of disease progression, and diagnosis were not associated as risk factors. Electroencephalogram modifications were associated with lower doses for treatment with quetiapine but not for specific antipsychotics. Electroencephalogram modifications and severe excitability were associated with higher chlorpromazine equivalent doses.

CONCLUSIONS

Atypical antipsychotics (clozapine, aripiprazole, quetiapine, olanzapine, and risperidone) induce EEG modifications, and these are significantly greater for clozapine and appear dependent on chlorpromazine equivalent dose. No encephalopathy was observed in these antipsychotic monotherapies, whatever dose.

Three clinical pearls in the treatment of patients with seizures and comorbid psychiatric disorders

A strong association exists between epilepsy and psychiatric comorbidities, especially depression, anxiety, attention deficit disorders, and psychosis. The impact of psychotropic medications in lowering seizure threshold both directly and indirectly, hypersensitivity reactions to antiepileptic and other psychotropic medications, and how antiepileptic drugs affect psychiatric disorders are explored through three patient cases. Ultimately, in selecting an appropriate psychotropic medication for an individual with epilepsy and psychiatric comorbidities, it is important to consider the clinical and quality-of-life impacts that a particular medication will have on that individual.

Daytime sleepiness and EEG abnormalities in patients treated with second generation antipsychotic agents

BACKGROUND

The aim of this study was to verify whether or not an increased prevalence of excessive daytime sleepiness (EDS) or EEG abnormalities is observed in patients with schizophrenia spectrum disorders (SSD), and to compare the effects of second generation antipsychotics (SGA) on patients' daytime sleepiness level and EEG recordings.

METHODS

EEG recordings and self-reports of EDS, assessed with Epworth (ESS) and Stanford (SSS) Sleepiness Scales, were compared between 244 patients with SSD and 82 patients with anxiety, personality or behavioral disorders (non-psychotic disorders, NPD). To examine the effects of various SGA, patients treated in monotherapy with aripiprazole, olanzapine, clozapine, risperidone and sertindole were compared.

RESULTS

A higher prevalence of abnormal EEG recordings was observed in SSD patients. No significant differences in average daytime sleepiness were found between patients with SSD and NPD; however, patients with SSD had longer sleep duration. Aripiprazole treatment was associated with significantly smaller and less frequent EEG abnormalities than treatment with any other SGA, while treatment with clozapine and olanzapine was related to an increased prevalence of severe EEG abnormalities. Patients with SSD treated with SGA in monotherapy were less sleepy than unmedicated patients with NPD.

CONCLUSIONS

Although antipsychotics may have profound effects on EEG patients with schizophrenia do not have higher daytime sleepiness than patients with anxiety/personality disorders. Patients with schizophrenia may compensate sedative effects of antipsychotic treatment with sleep duration prolongation and report even less sleepiness than non-psychotic patients.

Antipsychotics and seizures: higher risk with atypicals?

PURPOSE

Almost all antipsychotics have been associated with a risk of epileptic seizure provocation. Among the first-generation antipsychotics (FGA) chlorpromazine appears to be associated with the greatest risk of seizures among the second-generation antipsychotics (SGA) clozapine is thought to be most likely to cause convulsions. This information is largely based on studies that are not sufficiently controlled. Besides, information about the seizure risk associated with newer antipsychotics is scarce.

METHOD

The Pharmacovigilance Unit of the Basque Country (network of centers of the Spanish Pharmacovigilance System, SEFV) provided reporting data for adverse reactions (AR) from the whole SEFV to estimate the reporting odds ratio (ROR) for antipsychotics and seizures ("convulsions" as Single MedDra Query). Data was obtained from SEFV database from 1984 to the June 2011.

RESULTS

The total number of convulsions reported for SGA was 169 (total reported AR 3.204). The number of convulsions reported for FGA was 35 (total reported AR 2.051). 94 convulsions were reported in association with clozapine (total AR 1.052). The ROR for SGA versus FGA was 3.2 (CI 95%: 2.21-4.63). The ROR for SGA excluding clozapine versus FGA was 2.08 (CI 95%: 1.39-3.12).

CONCLUSION

Our results show that SGA may pose a higher risk of seizures than FGA, mainly, but not only due to clozapine. This is line with recent studies suggesting that some SGA carried a higher average risk of electroencephalographic abnormalities than many FGA. Nonetheless, It is well known that spontaneous reports do not allow strong inferences about adverse drug effects, because differences in reporting fractions by time, drug or type of event are difficult or even impossible to distinguish from differences in the occurrence rates of adverse events. Still, we consider that the possibility of SGA carrying a higher risk of seizure induction than FGA warrants further research.